1. Field of the Invention
This invention relates to an ice feeder for feeding ice chips to a beverage, such as iced coffee, which is capable of detecting no or insufficient stock of ice chips.
2. Prior Art
As a conventional ice feeder, there is an ice making apparatus proposed e.g. by Japanese Patent Publication (Kokoku) No. 61-13279, which comprises an auger-type ice making machine having an ice freezer for making ice chips and an ice container formed in one piece with the ice freezer for storing ice chips made by the ice freezer, and is adapted to feed a predetermined amount of ice chips to a cup based on a vend command supplied to the ice making apparatus. However, when vend products continue to be sold so frequently that production of ice chips cannot follow up feed or delivery thereof for use in vend products, the stock of ice chips in the ice container becomes insufficient for a vend product any longer. If products continue to be on sale in this state of the vending machine, a hot beverage would be supplied to a purchaser when he selected an iced beverage. Therefore, in general, the vending machine incorporates an ice feeder which is adapted to detect no or insufficient stock of ice chips to generate a signal indicative of this state of the ice container, based on which sales control is performed to inhibit iced vend products from being sold in such a state of the vending machine.
The detection of no or insufficient stock of ice chips is conventionally performed in the following manner: The auger-type ice making machine includes a limit switch arranged on the top of the ice container, which is turned on by upward pressure created by an increasing amount of ice chips within the ice container, and control means for starting calculation of a residual amount of ice chips when the limit switch is turned off after it has been turned on. More specifically, the control means initializes a count value of a counter incorporated therein when the limit switch is turned on, detecting fullness of the ice container, and starts to subtract, from the count value of the counter, a value proportional to the number of sales carried out thereafter while at the same time adding thereto a value proportional to an amount of ice chips made by the ice making machine, thereby calculating a residual amount of ice chips stored in the ice container. The control means determines from results of this calculation (i.e. the count value of the counter) that the ice container no longer holds a sufficient stock of ice chips for a vend product, and generates a no-ice-stock signal to the vending machine, which sets itself to a vend stop status in response to the no-ice-stock signal.
The ice chips are stored as a heap in the ice container, and dispensed in the order of lowermost chips to upper ones by the gravitational force of the heap. Therefore, an amount of ice chips supplied to a cup varies with a residual amount of ice chips heaped within the ice container. Furthermore, the amount of supply of ice chips also depends on an individual gate of the ice container for controlling delivery of ice chips and other component parts which are manufactured with inevitable variations among lots. Therefore, a final result of calculation of a residual amount of ice chips stored in the ice container by the above conventional method becomes unequal to an actual amount of ice chips stored in the ice container. This causes an erroneous determination that ice chips are out of stock in spite of the fact that the ice container holds a plenty amount of stock, or an incapability of detection of an insufficient stock of ice chips which is less than a predetermined supply amount, or even no stock of ice chips.
As a result, the ice feeder conventionally incorporated in a vending machine can be a cause of reduced sales of vend products due to inhibition of vending carried out when products (beverages) can be properly sold, or a cause of faulty sales of hot beverages to purchasers who selected iced beverages.